I am booked LHR-FRA-SIN-SYD next March.
LH778 has been brought forwards 10 minutes, was 21:55 now 21:45.
My inbound from London arrives 20:05 (It's often late, but I doubt that is taken into consideration)

I received an email saying that a change the the schedule means I will no longer be able to make my connection, however when I called the service centre they advised the MCT at FRA is 45 minutes.
They reiterated this twice, but the email implies that if I don't take action, my entire booking MAY get cancelled.

Any advice here?